Computational analysis of the early stage of cuprous oxide sulphidation: a top-down process

Abstract

The initial steps of Cu 2 O sulphidation to Cu 2 S have been studied using plane-wave density functional theory at the PBE-D3+U level of sophistication. Surface adsorption and dissociation of H 2 S and H 2 O, as well as the replacement reaction of lattice oxygen with sulphur, have been investigated for the most stable (111) and (100) surface facets under oxygen-lean conditions. We find that the (100) surface is more susceptible to sulphidation than the (111) surface, promoting both H 2 S adsorption, dissociation and the continued oxygen-sulphur replacement. The results presented in this proceeding bridge previous results from high-vacuum experiments on ideal surface to more realistic corrosion conditions and set the grounds for future mechanistic studies. Potential implications on the long-term final disposal of spent nuclear fuel are discussed. ARTICLE HISTORY

The local electron attachment energy and the electrostatic potential as descriptors of surface–adsorbate interactions

“…CO, H 2 S, H 2 O and methanol adsorption. [42][43][44] From the E S (r) map of the surface, we find that the Cu CUS sites indeed correspond to local minima, while the Cu CS sites are attributed lower Lewis acidity, i.e. lower electron affinity.…”

The anoxic corrosion behaviour of copper in the presence of chloride and sulphide

“…In recent years, the debate has gradually grown to consider the concept of "surface" thermodynamics (as opposed to conventional "bulk" thermodynamics). [22][23][24] The argument is that surface atoms, with a variety of nearest neighbour configurations, behave very differently from the bulk (terrace) atoms. The fewer the nearest neighbours, the lower the activation energy for atomic processes to occur: Surface diffusion, which permits rearrangement of the surface to a more thermodynamically stable state, and oxidation.…”

Complex reactions on a convertible catalyst surface: A study of the S-O-Cu system

“…is an important descriptor as well [8]. The Sulfur-Cu interaction has been addressed in several previous surface science studies, both experimentally [9][10][11][12][13][14][15][16][17][18][19][20] and theoretically [21][22][23][24][25]. Interest in this system arises not only from the use of Cu as desulfurization catalyst, but also from the S poisoning of the water gas shift reaction.…”

“…Interest in this system arises not only from the use of Cu as desulfurization catalyst, but also from the S poisoning of the water gas shift reaction. S induced corrosion of Cu plays an important role in the deterioration of cultural artefacts and is relevant for nuclear waste disposal, since the radioactive waste is sometimes confined in copper containers [25]. In the present study we revisit the interaction of Cu(110) and partially oxidized Cu(110) with Sulfur by scanning tunneling microscopy (STM).…”